Balancing energy barrier between states in perpendicular magnetic tunnel junctions

• US 9,472,748 B2
• Filed: 01/11/2016
• Issued: 10/18/2016
• Est. Priority Date: 12/30/2011
• Status: Active Grant

• Current Assignee: Tahoe Research Limited (f/k/a Learndale Limited) (Vector Capital Corporation)
• Original Assignee: Intel Corporation
• Inventors: Oguz, Kaan, Kuo, Charles C., Doyle, Brian S., Raychowdhury, Arijit, Mojarad, Roksana Golizadeh
• Primary Examiner(s): Byrne, Harry W
• Application Number:
  US14/992,601
• Publication Number:
  US 20160126452A1
• Time in Patent Office: 281 Days
• Field of Search: 365/48, 365/55, 365/62, 365/66, 365/74, 365/78, 365 80- 93, 365/100, 365/130, 365/131, 365/148, 365/158, 365171-173, 365/209, 365/213, 365/225.5, 365/230.07, 365/232, 365/243.5, 257/421, 257/E21.665, 438/3, 977933-935
• US Class Current: 1/1
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: G11C 11/1673 Reading or sensing circuits or methods
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/80 Constructional details

Abstract

Techniques are disclosed for enhancing performance of a perpendicular magnetic tunnel junction (MTJ) by implementing an additional ferromagnetic layer therein. The additional ferromagnetic layer can be implemented, for example, in or otherwise proximate either the fixed ferromagnetic layer or the free ferromagnetic layer of the perpendicular MTJ. In some embodiments, the additional ferromagnetic layer is implemented with a non-magnetic spacer, wherein the thickness of the additional ferromagnetic layer and/or spacer can be adjusted to sufficiently balance the energy barrier between parallel and anti-parallel states of the perpendicular MTJ. In some embodiments, the additional ferromagnetic layer is configured such that its magnetization is opposite that of the fixed ferromagnetic layer.

Claims

1. An integrated circuit, comprising:

a substrate; and

a magnetic tunnel junction formed at least one of in or on the substrate, wherein the magnetic tunnel junction comprises;

a first insulator layer sandwiched between a free ferromagnetic layer and a fixed ferromagnetic layer, wherein each of the free and fixed ferromagnetic layers are associated with a magnetization direction; and

a second insulator layer sandwiched between a third ferromagnetic layer and one of the free or fixed ferromagnetic layers, wherein the third ferromagnetic layer is associated with a magnetization direction that is opposite the magnetization direction of the fixed ferromagnetic layer.

2. The circuit of claim 1, further comprising one or more electrical contacts operatively coupled with the magnetic tunnel junction, wherein a parallel or anti-parallel state of the magnetic tunnel junction is determined by passing a current therethrough.

3. The circuit of claim 1, wherein the first insulator layer comprises magnesium oxide and the second insulator layer comprises ruthenium.

4. The circuit of claim 1, wherein the circuit is implemented in a memory circuit.

5. The circuit of claim 4, wherein the memory circuit is at least one of embedded memory, non-volatile memory, magnetoresistive random-access memory, spin transfer torque memory, volatile memory, static random-access memory, and dynamic random-access memory.

6. An electronic device comprising one or more of the integrated circuit of claim 1.

7. The electronic device of claim 6, wherein the device comprises at least one of a memory circuit, a communication chip, and a processor.

8. A computing system comprising one or more of the integrated circuit of claim 1.

9. The computing system of claim 8, wherein the system is a mobile computing system.

10. A magnetic tunnel junction circuit, comprising:

a free ferromagnetic layer having a magnetization direction;

a fixed ferromagnetic layer having a magnetization direction;

a third ferromagnetic layer having a magnetization direction;

a first insulator layer sandwiched between the free ferromagnetic layer and the fixed ferromagnetic layer; and

a second insulator layer sandwiched between the third ferromagnetic layer and one of the free or fixed ferromagnetic layers;

wherein the magnetization direction of the third ferromagnetic layer is opposite the magnetization direction of the fixed ferromagnetic layer.

11. The circuit of claim 10 further comprising a first electrical contact operatively coupled with the free ferromagnetic layer, a second electrical contact operatively coupled with the third ferromagnetic layer.

12. The circuit of claim 10, wherein the first insulator layer comprises one of magnesium oxide or ruthenium, and the second insulator layer comprises the other of magnesium oxide or ruthenium.

13. The circuit of claim 10, wherein the circuit is implemented in a memory circuit.

14. The circuit of claim 13, wherein the memory circuit is at least one of embedded memory, non-volatile memory, magnetoresistive random-access memory, spin transfer torque memory, volatile memory, static random-access memory, and dynamic random-access memory.

15. An electronic device comprising one or more of the magnetic tunnel junction circuit of claim 10.

16. The electronic device of claim 15, wherein the device comprises at least one of a memory circuit, a communication chip, and a processor.

17. A computing system comprising one or more of the magnetic tunnel junction circuit of claim 10.

18. The computing system of claim 17, wherein the system is a mobile computing system.

19. A method of making an integrated circuit, the method comprising:

providing a first insulator layer sandwiched between a free ferromagnetic layer and a fixed ferromagnetic layer; and

providing a second insulator layer sandwiched between a third ferromagnetic layer and one of the free or fixed ferromagnetic layers.

20. The method of claim 19 further comprising providing one or more electrical contacts operatively coupled with one or more of the ferromagnetic layers.